Setting Up A Software PABX

I hate switchboards.  This ubiquitous piece of office hardware has always seemed to be the biggest equipment rip-off that any business owner has to suffer.  Paying lots of cash for a primitive switching system that comes with built in limitations tends to set me off a bit.  Beyond that are some of the associated costs that come with moving from no phone system to a PABX system for your growing business.

In my previous company, one of the major limitations that drove us out of our home office and into a “real” office was the need to get more phone lines and have phone switchboard functionality, such as transferring calls or sharing one phone line between several people.  Real offices can be great, but they also add a lot of expense, and since we would like to keep running RightSite out of our home/office even while adding more staff and making more phone calls, we are looking into installing a software PABX called trixbox.

Trixbox is supposed to provide us with advanced switchboard functionality including voicemail, call forwarding and other functions, and lets us hook our phone system directly into a VOIP (Voice Over Internet Protocol) system so that there will be no more long distance charges. This free software is installed on a server and connected both to the phone lines and your computer network.  Phone calls can be taken through workstations, on special IP phones, or on regular telephones, depending on how you want to set up your system.  Pretty groovy (especially the “free” part).

But now Mike has to figure out how to integrate the trixbox system into his network.  The system itself appears easy to set up, but figuring out how it works with the rest of our network is challenging for a techno-dunce like me.  Here’s how I think it would work:

Phone/ASDL line
Phone line comes into modem from somewhere outside my apartment

Modem
Modem connects data line to router
Modem connects voice line to Trixbox server

PSTN Interface card
Connects PSTN (phone) line to trixbox server

pfSense Router/Firewall
router distributes data to network workstations and servers via data network

trixbox Server
trixbox server distributes voice traffic to workstations or IP phones via data network

Data network
Carries data and voice traffic to workstations and IP phones

An ugly diagram of how I think this system might work is available here, courtesy of the nice folks at scribd.com

The problem that I have with this network concept is that right now the trixbox server sits outside of the firewall, which makes the network vulnerable to hackers.  So I expect that before we can implement this network, I will need to figure out how to set up the trixbox server within the network, but still make it accessible to the PSTN (regular old phone) lines.

If any of you more technically astute people out there have suggestions, please feel free to comment!